Assess seed coat and seed tissue resistanace to A. flavus colonization and aflatoxin production. Survey association of navel orangeworm damage to kernels and aflatoxin contamination. Characterize shell structure components critical to integrity of the almond shell seal. Identify genetic mechanisms and genotypes for controlling aflatoxin contamination in almonds.
The stability of genetic resistance mechanisms will be assessed in 25 diverse almond genotypes and tested for fungal colonization, aflatoxin and shell seal. Nut damage by insects and aflatoxin contamination will be assessed on harvested and industry rejected samples to determine the relationship between aflatoxin and specific kernel damage by insects. Mature shell structure components will be identified and characterized by examination of cross sections of soft and hard shell varieties of almond especially the variety "Ruby". The most effective genetic mechanisms and genotypes for developing almons resistant to aflatoxin will be identified. Possiable techniques are particle-gum bombardment, developing interspecific mosaic genetic tissue plants, and spontaneous plant chimeras. (Formerly 5325-42000-031-07S - 09/04)